Daniel Tammet: 'Maths is as rich, inspiring and human as literature is.' Photograph: David Levene for the Guardian

British writer Daniel Tammet is a mathematical savant with Asperger's syndrome and synaesthesia. His third book, Thinking in Numbers: How Maths Illuminates Our Lives, is a collection of 25 essays exploring mathematics as "the science of imagination". He is also a gifted linguist.

You realised you were different from an early age, and were bullied at school…

Yes, I was very different and for a reason that seems invisible. Other children sniff out these differences, I was called names and teased. But I had no diagnosis at school. Asperger's syndrome only came in officially as a diagnosis in 1994. I had difficulties with understanding social interactions and problems with hygiene, but I managed to control my behaviours and I was under the radar for another few years. When I achieved the European record for reciting pi in 2004, this captured the imagination of Professor Simon Baron-Cohen in Cambridge and he finally diagnosed me with Asperger's that year.

Was your diagnosis a relief?

A huge relief, because I could stop feeling guilty. Guilty about not going to university. I didn't have many friends and I also blamed that on myself, for being lazy or cack-handed. But now, with the diagnosis, I knew that I had developed differently.

What about life today? In your first book, Born on a Blue Day, you mention your need for routine, which is very common in autism – having to weigh out your breakfast precisely every morning, for instance.

Well, I now spoon out the cereal! I do still have a sense of control and routine but this is much less of an issue now. That book was written while I was wrestling with my childhood. I was incredibly lucky that my first book found a large and loyal readership. It changed my life – from being a very withdrawn adult to living in Paris as a full-time writer. It has also given me enormous confidence.

Do you think your love of languages is inspired by the fact languages, although organic, are rules-based, and people with AS enjoy rules?

Certainly. But the rules can be bent and played with. Like mathematics, languages are a great source of creativity. Maths is as rich, inspiring and human as literature is.

You used to read lots of biographies as a teenager. Which books do you enjoy reading today?

GK Chesterton was an early inspiration for Thinking in Numbers – especially his essays. I have surprised myself by moving into fiction. Fiction has taught me about maths – they are much more similar than people tend to believe. Both respond to fundamental questions about life. Both deal with meaning – in maths, it is about the nature of a point, a line or a square. I've tried to bring storytelling to mathematics. There are very few readable books about maths. I'm not a professional mathematician and I find abstractions very difficult, but I love the detail.

In Thinking in Numbers, you refer to Julio Cortázar's novel, Rayuela (Hopscotch), which can be read in any order. Was the appeal of that book mathematical, aesthetic or a fusion of both?

Aesthetics interests me most. Aesthetics – rather than reason – shapes our thought processes. First comes aesthetics, then logic. Thinking in Numbers is not about an attempt to impress the reader but to include the reader, draw the reader in, by explaining my experiences – the beauty I feel in a prime number, for example. Prime numbers can be poetic. I want to break down the barrier between fiction and non-fiction. I want to bruise the line by coming up against it.

There is moving chapter about your mother in Thinking in Numbers, which describes how you came to realise that she – like everyone else – was not perfect.

Yes. The chapter is called A Model Mother, which is a play on words. My mother is not a model. She is not perfect. That awareness is part of learning to love someone. Predicting the actions of someone is an act of love. We persist, even when we get it wrong. That's the beauty of love. But this was a big lesson for a child with autism – the fact that we all make mistakes.

When did you first notice your synaesthesia?

That's hard to say, because when I saw the number 9 as dark blue, I assumed everyone felt like that! In my case, numbers and language feed into each other. They are mutually nourishing. My synaesthesia is enormously enriching, as it was for Vladimir Nabokov. And my autism informs my writing, because of my experience as an outsider. Numbers were my friends – I didn't have any others. I now have friends and a partner, Jérôme. People with autism are just as capable of falling in love as anyone else.

Are you working on a new book?

I hope to write a novel based on the 1972 Fischer-Spassky chess match in Reykjavik. I have lots of friends there and I am collecting anecdotes about the match right now.